Char revivification apparatus including means for reclaiming and reutilizing heat from the cooling section thereof



Nov. 4, 1947.

R. s. KENT CHARAREVIVIFICATION APPARATUS INCLUDING MEANS FOR RECLAIUING AND HEUTILIZINGV HEAT FROM THE COOLING SECTION THEREOF 2 Sheets-Sheet 1 Filed Dec. 16, 1944 //lf. //M /A. 7 a, h.

u F, .M V 0 R. S. KENT RATUS INCLUDING MEANS FOR REGLA Nov. 4, 1947. 2,430,056

CHAR Rvsvrvwrcmxow APPA l mme ma REU'fILIzmG HEAT FROM THE comme sEcTIoN TnEREoF File. Dec.. 16, 1944 2 sheets-sheet 2 ,.Hnm..n,..

w Wmv falaz-t Wfl/1111111011111? Patented Nev. 4, 1947 CHAR REVIVIFICATION APPARATUS MEANS FOR RECLAIMING G HEAT FROM. THE

CLUDIN G RE sEc'rroN 'rnEnEoF Robert Sayre Kent, Brooklyn, N. y. Application neeember 1c, 1944, serial No. seam 4 claimt.Y (ci. 2oz-1z0) This invention relates to improvements in apparatus for reviviiying nitrate material, such as char or boneeblack, after use thereof for ilteringl liquors in the process of reilning sugar.

It is well known in the sugar reilning industry that illtrate material, such as char or bone-black, after the same has been used in ltration operam.. AND COOLING mation eii'ect, also cooperates with the retort means in such manner as to substantially improve and accelerate the discharge oi' vapors and gases tions, maybe substantially dried and then reviviiled and freed from accumulated excess carbon content and other impurities by baking the same in a kiln or retort, whereby the impurities collected in the pores of the char particles are burnt or distilled oiY, so that the illtering value of the char is brought back to practical elciency. One type of apparatus commonly employed for such Achar revivification comprises dryer means, retort means and cooler means so relatedl that the char to be treated may ilow by gravitation through the dryer means, thence Athrough the retort means, and nally through the cooler means, being discharged from the latterin the required revivified condition ready for reuse. In such type of apparatus, the dryer means is so constructed as to dispose the char, gravitating therethrough, in a relatively. thin layer-subject to application of heat thereto tor driving oil! moisture therefrom. 'Ihe thus dried char is discharged irom the dryer for delivery `and gravitation through highly heated retort means, which is also provided with means for disposing the char gravitating therethrough in relatively thin mass in contact with the highly heated retort walls, said latter means including' means for venting from the retort the vapors and gases liberated from the char by the baking process. The baked char, which leaves the retort means at a high temperature (approximately 800 F.) is caused to gravitate through the cooler means, whereby. heat is transferred from the char and its temperature greatly reduced (to approximately 200 F.) so that the reviviiled char is insultably cooled condition for delivery to char ilters.

'Ihis invention has i'or` an object to provide. in char reviviiying apparatus of the type above referred to, novel means for reclaiming heat given and with` the upper-part of the dryer section.,

l .4 4, and s--t,1n rig. 2,

of! by the cooling char 'which traverses the cooling means, which heat has and returning said heat whereby to increase the generally been wasted, to the retort means, eiiiciency of the latter. so that speedier iiow therethrough of char under treatment may be attained, and consequently so that a greater quantit of char per unit of time may be eectively puried.

Another object or this invention is to provide novel means which, in addition toits heat reclachamber Il is located the given oiI by the char undergoing baking treatment in such retort means.

vOther objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description oi' the same.

char revivifylng apparatus according to thisinvention, with parts thereof shown in elevation,

thereof'broken away.

Fig. 2 is a fragmentary vertical longitudinal sectional view of a retort member of the avxiay ratus and the cooler tube connected there said view being drawn on an enlarged scale; and Figs. 3, 4 and 5 are respectively horizontal cross sectional views, taken respectively on lines 3 3, said views being drawn on a further enlarged scale. y

Similar characters oi' reference are employed in the above described views, to indicate corresponding parts.

Referring to the drawings,- the reference character I0 indicates a kiln of well known construction adapted to contain and heat a series oi.'- retorts through which char, desired to be revivified by baking, is caused to gravitate. Said kiln is provided with the usual central combustion chamber -II enclosed by side walls I2, top arch il and oo'r wall I4. Beneath the combustion usual air box l5. On opposite sides of the combustion chamber Il are located retort chambers i6, through which extend a plurality or suitably supported tubular retorts Il. The lower ends of the retorts Il are supported by bottom caps I8 which are seated upon the floor I9l oi.' the kiln lil. The upper ends of the retorts i1 are supportedby the dependent tubular necks 2li of latter being suitably suppo to'close the upper ends of the retorteham rs I8; the passages 22 of said necks serve to admit char into and for descent through the retorts. The products or hot gases of combustion generated within the combustion chamber il pass into the upper ends of the retort chambers I6 through entrance ports 23 provided in the side walls l2 i' said combustion chamber. The .products or hot gases of top or cover plates Il, the

bers I6, circulate around the retorts I1 and pass downwardly along the same, being discharged from the retort chambers through exit ports 24, escaping thence through suitable channels to the dryer means presently to be described and thence to azstack (not shown).

Mounted on top of the kiln I isa dryer means of the general kind shown in my prior United States Letters Patent #984,931, and 1,962,643. This dryer means is provided with a central chamber 25 through which is suitably passed the gases and products of combustion out going from the kiln, to be thence discharged through the kiln stack (not shown) thus providing heat for preliminary drying of the moist char which is delivered to and passed through the dryer means preparatory to delivery to the retorts I1. The sides of the dryer means are kformed by inner zigzag walls 26. Outwardly offset from said Zigzag walls 26 are a series of suitably spaced downwardly and inwardly inclined external plates 21.-

thus forming an intermediate char passage through which moist char may gravitate in a relatively thin layer. The heat applied to this thin layer of char drives off the major part of its moisture content, the resulting vapors escaping to the atmosphere through the open spaces bc tween said external plates 21. The lower dis,- charge ends of the char passages of the dryer means communicate with char receiving hoppers 28, which are located above the upper ends of the kiln retort chambers I6. Extending from said hoppers 2B are feed pipes 29 which enter the upper ends of the kiln retorts I1, whereby the preliminarily dried char discharged from the dryer means may gravitate to and enter said retorts for descent therethrough.

Extending downwardly from the lower discharge ends of the retorts I1 are cooler tubes 30. The lower ends of said cooler tubes are supported by bottom caps 3|, which are in turn supported by carrier frames 32. Said carrier frames 32 are suspended by tie-rods 33 dependent from the kiln' floor I9. The upper ends of said cooler tubes 30 are supported by tubular necks 34 which prol ject from the undersides of the retort bottom caps' I8; the passages 35 of said necks 34 serve to admit char, discharged from the retorts, into and for descent through said cooler tubes 30. The bottom caps 3| which support the lower ends of the cooler tubes are provided with passages 36 through which the reviviled and cooled char is discharged to suitable receiving means (not shown) ,l whence it may be taken to filters or like means (not shown), to be there stored until reuse thereof in filtration operations is desired.

Extending through the interior of each retort I1, from bottom to top thereof, is a tubular conduit 31. The lower end of said conduit 31 is supported by a transverse bridge piece 38 which spans the passage of the retort bottom cap I8,

being held in position by the engagement thereof over a coupler spout 39 upstanding from said bridge piece. Asuitably predetermined extent of the lower portion 40 of said conduit is imper forate, while the upper portion thereof is perforate to provide a vapor collector section 4I,

whereby gases and vapors given oil by the heated kchar within the retort pass through the perforations or ports 42 into the interior of the collector section 4I, so as to be collected therein and vented therefrom. The walls of the conduit 31 are suitably formed to provide external downwardly and outwardly flared annular flanges 43. Those flanges 43 which extend from the collector perforate lower portion 40 of the conduit, so that the flanges are provided along substantially the entire length of the conduit 31, whereby to cause the char gravitating through the retort to flow in relatively thin mass along and in intimate contact with the highly heated retort walls. At its upper end,- said conduit 31 terminates in a discharge extension 44, which projects upwardly through the tubular neck 20 of the top or cover plate 2I of the retort, so as to communicate with a chamber 45 disposed intermediate the retort chamber -I 5 and the char feed hopper 28. Leading from the chamber 45 is a port 46 which communicates with a flue 41 provided in the kiln structure; said nue serving to discharge vapors and gases, emitted from the retorts- I1, to the kiln stack.A l

Extending axially through the interior of each cooler tube 30 is an air induction pipe 48. The lower end of said air induction pipe is supported on a transverse bridge piece 49 which spans the passage 36 of cooler tube bottom cap 3l. At its lower end, said air induction pipe 48 is provided with at least one transverse intake member 50 which extends through the cooler tube wall, so that its outer end is open to the atmosphere externally of the cooler tube. The upper end of Ycap I8, and in engagement over a coupler spout 5I dependent from the bridge piece 38 of the retort bottom alignment with the opstanding coupler spout 39 of the latter. Said spouts 39 and 5I provide a connecting passage 52 between the air induction pipe 48 and the conduit 31 of the retort I1 which is above the cooler tube through which said a'ir induction pipe extends.

In operation, char that has been used and wetted in filtration operations is nrst passed through the dryer means, whereby its moisture content is driven off. From the dryer means, the char, which ordinarily still contains from 6 to 12 per cent moisture, is delivered into the tops of the retorts I1 for gravitation therethrough, and so as to be subjected to the revivifying effect of high heat, usually approximately 800 F. At

400 F., the volatile carbon compounds contained in the char are vaporized so as to be capable of being vented therefrom, while at 800 F., foreign xed carbon is reduced to ash and gas. The char treated in a retort I1, discharges from the lower end thereof at a temperature of about 800 F., and must be cooled down to about 200 F. The cooling of the char is effected during descent thereof through a cooler tube 30, whereby heat is ordinarily transferred from the char entirely through the cooler tube walls to the ambient atmosphere. Heat thus dissipated is usually wasted, although some attempt has been made to return it by circuitous route to the dryer means in aid of the preliminary char drying operation performed in the latter, but no effective means has heretofore been provided for reclaiming such heat in aid of the char baking operation performed in a retort. The instant invention however provides means for reclaiming heat transferred from the char traversing a cooler tube, and thereupon returning such heat to the retort in. aid of the char baking operation carried on follows:

Atmospheric air enters the intake means 50 at the bottom end of an air induction pipe 48, so as to rise through the latter. Since saidr air induction pipe 48 is surrounded by the hot char in the cooler tube 30, through which said pipe 48 extends, heat will be transferred from said char to the column of air ascending said pipe 48, thus charging said air with thermal units. The thus heated air is delivered from the pipe 48 into thel conduit 31 within the retort I1 above, thereb7 yheating the walls of said conduit, and especially the lower imperforate section 40 of said conduit, and consequently aiding application of heat to the char undergoing treatment in said retort. The lower section 40 of the conduit 31 being imperforate, will permit no ingoing air to escape into the surrounding char, which char attains maximum temperature in the lower end portion ofthe retort, and consequently no risk of combustion and destruction of active carbon of the char, which is desired to be conserved, occurs. The air thus delivered into the lower end of the conduit 31, in ascending therethrough, iiows onward through the perforate vapor collector section 4| of said conduit, and is finally discharged from the upper end of the latter to pass thence to the ilue 41, and to the kiln stack with which the latter communicates. The natural draft thus provided, maintains flow of air into and through the air induction pipe 48 and thence through the conduit 31. The movement of air through the perforate vapor collector section 4| assists materially in drawing into the latter the vapors and of retort kiln shown in the drawings and herein` above described has been so shown and described char in said retort member by transfer through the walls of said conduit primarily by conduction through the lower imperforate section of the latter.

2. In a kiln for the purposes described, a retort member and a cooler tube coupled in end to end vertically disposed and communicating relation, an air induction pipe extending axially through the interior of said cooler tube in direct contact with the hot char descending the latter, said pipe having air intake means open to the atmosphere exteriorly of the lower end of said cooler tube, a conduit extending` axially through said retort member, said conduit having a lower imperiorate section and an upper perforate section, said perforate section providing means to collect and vent vapors and gases liberated from the char under treatment in said retort member, means to' couple said pipe and conduit in end to end communicating relation, whereby heat from char descending said cooler tube from said retort member may be transferred through the walls of said pipe to the air ascending therein and thereby returned to char in said retort member by transfer through the walls of said conduit primarily by conduction through the lower imperforate section of the latter, and means to discharge air and collect vapors and gases from the perforate upper end of said conduit with draft effect induced by said air flow.

3. In a kiln for the purposes described as defined in claim 1, wherein said conduit is provided with longitudinally spaced external outwardly and downwardly flaring annular flanges, certain of said flanges guarding the openings of the perforato section of said conduit against access by merely by way of illustration and not by way of exteriorly of said cooler tube, a conduit extending axially through said retort member, said conduit having a lower imper'forate section and an upper perforate` section, said perforate section providing means to collect and vent vapors and gases liberated from the char under treatment in said retort member, and means to couple said pipe and conduit in end to end communicating relation, whereby heat from char descending said cooler tube from said retort member may be transferred through the walls of said pipe to the air ascending therein and thereby returned to the char within the retort member, and said flanges in their entirety being adapted to cause the char gravitating through the retort' member to flow in relatively thin mass along and in intimate contact with the retort member walls.

4. In a kiln for the purposes described as defined in claim 2, wherein said conduit is provided with longitudinally spaced external outwardly and downwardly aring annular flanges, certain of said flanges guarding the openings of the per forate section of said conduit against access by the char `within the retort member, and said flanges in their entirety being adapted to cause the char gravitating through the retort member to ow in relatively thin mass along and in intimate contact with the retort member walls.

ROBERT SAYRE KENT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date f 293,430 Eastwick Feb.` 12, 1884 303,378 Matthiessen Aug. 12, 1884 308,476 Eastwick Nov. 25, l1884 592,547 Krause Oct.,26, 1897 1,418,970 Pool June 6, 1922 1,704,093 Marshall Mar. 5, 1929.

FOREIGN PATENTS Number Country Date 203,908 Switzerland 1939 

